@foxglove/chartjs-plugin-zoom

chartjs-plugin-zoom

A zoom and pan plugin for Chart.js >= 3.0.0-beta.13.

For Chart.js 2.6.0 to 2.9.x support, use version 0.7.7 of this plugin.

Panning can be done via the mouse or with a finger. Zooming is done via the mouse wheel or via a pinch gesture. Hammer.js is used for gesture recognition.

Live Codepen Demo

Installation

Run npm install --save chartjs-plugin-zoom to install with npm.

If including via a <script> tag, make sure to include Hammer.js as well:

<script src="https://cdn.jsdelivr.net/npm/chart.js@next"></script>
<script src="https://cdn.jsdelivr.net/npm/hammerjs@2.0.8"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-plugin-zoom@next"></script>

Configuration

To configure the zoom and pan plugin, you can simply add new config options to your chart config.

plugins: {
 zoom: {
  // Container for pan options
  pan: {
   // Boolean to enable panning
   enabled: true,

   // Panning directions. Remove the appropriate direction to disable
   // Eg. 'y' would only allow panning in the y direction
   // A function that is called as the user is panning and returns the
   // available directions can also be used:
   //   mode: function({ chart }) {
   //     return 'xy';
   //   },
   mode: 'xy',

   // Which of the enabled panning directions should only be available
   // when the mouse cursor is over one of scale.
   overScaleMode: 'xy',

   rangeMin: {
    // Format of min pan range depends on scale type
    x: null,
    y: null
   },
   rangeMax: {
    // Format of max pan range depends on scale type
    x: null,
    y: null
   },

   // On category scale, factor of pan velocity
   speed: 20,

   // Minimal pan distance required before actually applying pan
   threshold: 10,

   // Function called while the user is panning
   onPan: function({chart}) { console.log(`I'm panning!!!`); },
   // Function called once panning is completed
   onPanComplete: function({chart}) { console.log(`I was panned!!!`); },
   // Function called when pan fails because modifier key was not detected.
   // event is the a hammer event that failed - see https://hammerjs.github.io/api#event-object
   onPanRejected: function({chart, event}) { console.log(`I didn't start panning!`); }
  },

  // Container for zoom options
  zoom: {
   // Boolean to enable zooming
   enabled: true,

   // Enable drag-to-zoom behavior
   drag: true,

   // Drag-to-zoom effect can be customized
   // drag: {
   //   borderColor: 'rgba(225,225,225,0.3)'
   //   borderWidth: 5,
   //   backgroundColor: 'rgb(225,225,225)',
   //   animationDuration: 0
   // },

   // Zooming directions. Remove the appropriate direction to disable
   // Eg. 'y' would only allow zooming in the y direction
   // A function that is called as the user is zooming and returns the
   // available directions can also be used:
   //   mode: function({ chart }) {
   //     return 'xy';
   //   },
   mode: 'xy',

   // Which of the enabled zooming directions should only be available
   // when the mouse cursor is over one of scale.
   overScaleMode: 'xy',

   rangeMin: {
    // Format of min zoom range depends on scale type
    x: null,
    y: null
   },
   rangeMax: {
    // Format of max zoom range depends on scale type
    x: null,
    y: null
   },

   // Speed of zoom via mouse wheel
   // (percentage of zoom on a wheel event)
   speed: 0.1,

   // Minimal zoom distance required before actually applying zoom
   threshold: 2,

   // On category scale, minimal zoom level before actually applying zoom
   sensitivity: 3,

   // Function called while the user is zooming
   onZoom: function({chart}) { console.log(`I'm zooming!!!`); },
   // Function called once zooming is completed
   onZoomComplete: function({chart}) { console.log(`I was zoomed!!!`); },
   // Function called when wheel input occurs without modifier key
   onZoomRejected: function({chart, event}) { console.log(`I didn't start zooming!`); }
  }
 }
}

API

chart.resetZoom()

Programmatically resets the zoom to the default state. See samples/zoom-time.html for an example.

Documentation

You can find documentation for Chart.js at www.chartjs.org/docs.

Examples for this plugin are available in the samples folder.

Prior to v0.4.0, this plugin was known as 'Chart.Zoom.js'. Old versions are still available on npm under that name.

Contributing

Before submitting an issue or a pull request to the project, please take a moment to look over the contributing guidelines first.

License

chartjs-plugin-zoom.js is available under the MIT license.